1997 Vmax 500 XT Mid range rough using lots of gas

MrSled said:
I would clean the carbs again. Make sure to either replace the pilots or get new ones. New plugs, new belt and then look over the clutches( Rollers. Weights, center bushings ) Also be sure that the throttle cable at the split is pushed back together and not apart. The inlet needs and seats could be a problem as well in the carbs. Does it start easy almost with no choke?
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You asked about starting easily with almost no choke? After getting it all back together and not seeing a big difference until I drained gas then I seen a slight change. This morning after letting it sit over night in the cold I went out and just for the heck of it check sparkplug boots and took some off and re-installed. Went to start it and never turned choke on and sled started right up with probably only a half a pull. Sounding a little better. If starting with no choke what should I look for??
 
MrSled said:
The reason I asked is when it will start with no choke sometimes the inlet needs will seep and cause it to run like that.
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When you say inlet needles are you referring to the ones that the fliats attach to? Will be honest I do not believe the shop remived the floats and pulled needles. I know I didnt either just ran carb cleaner through them. Maybe that is the running rich issue too?
 
stugny said:
When you say inlet needles are you referring to the ones that the fliats attach to? Will be honest I do not believe the shop remived the floats and pulled needles. I know I didnt either just ran carb cleaner through them. Maybe that is the running rich issue too?
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Yes the ones attached to the floats. When they get old they can seep and it would be getting fuel even when the float is suppose to be not allowing it.
 
Ok looks like carbs are coming back off. Probably wait for warmer weather and do the reed mod too. Thanks
 
First, if I recall your sled has flatslide carbs TM36's. They are a Mother of a PIA to clean correctly. If its brass it neeads to come out. All the little jets on the inlet side of the carbs come out. Use fishing line to clean them. I use old guitar strings. The slides and emulsion tube are notorious for wear.. on the idle screws there are Orings. Replace them. They suck to get out if they sick in the carb body.. I tank my carbs for 8hrs in carb cleaner. After that they get rinsed in water and go into a heated ultrasonic cleaner for 3 4 min cycles. Put back together low sped set to factory spec. Floats set to spec. Slides set to 1.3mm open on both carbs. Back in machine they go. Start it. Let it run till rear heat exchanger is warm set idle. Shut it down. Pull off boost bottle. Plug the port on the pto side. Vac gage on mag side take reading. Swap sides take reading. Should be close. If not pull the top cover off the pto side carb and adjust ecentric screw. Vac is always tested with the carb covers on and tight... As long as no parts are out of tolerance carbs should be back to normal. I have the factory manual if you need and specs pm me.
 
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Mbstorrs said:
First, if I recall your sled has flatslide carbs TM36's. They are a Mother of a PIA to clean correctly. If its brass it neeads to come out. All the little jets on the inlet side of the carbs come out. Use fishing line to clean them. I use old guitar strings. The slides and emulsion tube are notorious for wear.. on the idle screws there are Orings. Replace them. They suck to get out if they sick in the carb body.. I tank my carbs for 8hrs in carb cleaner. After that they get rinsed in water and go into a heated ultrasonic cleaner for 3 4 min cycles. Put back together low sped set to factory spec. Floats set to spec. Slides set to 1.3mm open on both carbs. Back in machine they go. Start it. Let it run till rear heat exchanger is warm set idle. Shut it down. Pull off boost bottle. Plug the port on the pto side. Vac gage on mag side take reading. Swap sides take reading. Should be close. If not pull the top cover off the pto side carb and adjust ecentric screw. Vac is always tested with the carb covers on and tight... As long as no parts are out of tolerance carbs should be back to normal. I have the factory manual if you need and specs pm me.
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Thanks looks like I have my work cut out for me. I do not have acces,to an ultra sonic machine may have to take somewhere? How can you tell if slides and emulsion tubes are worn? When you say emulsion tubes are you referring to the brass insert the needle rides in?
 
Yep. Those wear out just like the slides do... ill post the carb stuff here as well. There is a post for another vmax with similar probs.. the TM36's are awesome when they are in good shape, but one little problem and they make life hell to work on..
 
Carb tuning

Good luck keep me posted...
 

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When you spoke of vacuum what sort of number should I be looking for? Wasn't sure what equipment I need to test?
 
WOW! Thanks for sharing that pic. I would never have thought that much "wear" would be possible. Learn something new everyday. Now I have a bunch of carb racks that need to be inspected!
 
The pics shows the wear pretty obvious. Is there a spec they should be at if not as obvious?
 
Now if I can only find the part. No one had them in stock. Only see one on ebay and that is from Japan ��
 
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